Electric traveling crane system



Jan, 8, 1946. R. w. sPAFFoRD ETAL 2,392,417

ELECTRIC TRAVELING CRANE SYSTEM 3 5 Sheets-Sheet l Filed Sept.

fill/@fors EaZ/9h WSpczO/'d R. w. sPAFFoRD Erm. 2,392,417

ELECTRIC TRAVELING CRANE SYSTEM Jan. 8, 1946.

Filed Sept. ll, 1943 5 Sheets-Sheet 2 m. INQI Se If figo/72e S.V

Jan. 8, 1946. R. w. sPAFr-'ORD ETAL 2,392,417

ELECTRIC TRAVELING CRANE SYSTEM 5 Sheets-Sheet 5` Filed sept. 11, 1943Ralph W? Lz d paffo/'d Jan. 8, 1946. R. w. sPAFFoRD ETAL. 2,392,417

ELECTRIC TRAVELING CRANE SYSTEM FiledSept. 13., 1943 5 Sheets-Sheet 4Jan. 8, 1946. R. w. sPAFFoR-D ETAI. 2,392,417

ELECTRIC TRAVELING CRANE SYSTEM Filed Sept. 11, 1943 5 Sheets-Sheet 5Patented Jan. 8, 19.46

2,392,417 y ELEc'rmcrRAvELING CRANE SYSTEM Ralph W. Spaiford and LloydR. Bergren, Fairfield, Iowa, assignors to The Londen1 Machinery Company,Fairfield, Iowa, a corporation of Iowa Application September 11, 1943,Serial No. 501,958

Claims.

Our invention relates to an electric traveling crane system.

One of the objects of our invention is to provide in an electrictraveling crane system comprising a bridge carrying a bridge motor andtraveling along a runway and provided with a power circuit, a collectorengaging control circuit for the bridge motor running along said bridge,and a trolley traveling along the bridge and carrying a motor, apparatuswhereby the operator travelingalong with the trolley (either on foot orin a cage car ried by the trolley) can control the bridge motor tocontrol the bridge travel and can cause the trolley to leave the bridgetrack and travel off onto a spur track where the trolley-carried motoralone is used, in which the bridge-carried control circuit for thebridge motor is in alignment with the {bridge-carried power circuit forthe trolleycarried motor or motors, so that the same collectors maycooperate both with the power circuit and the lcontrol circuit, thusavoiding the necessity for non-current-carrying guide rails along thespur track.

Further objects and advantages of the invention will be apparent fromthe specification and claims.

In the drawings, in which two embodiments oi our invention are shown,

Figure 1 is a Side elevational view of the bridge and trolley;

Fig. 2 is an end elevation of the bridge truck;

Fig. 3y is la plan view showing portions of the bridge and bridgerunways;

Fig. 4 is a diagrammatic View showing the circuits with the trolley inone position;

Fig. 5 is a View similar to Fig. 4 showing the trolley in a differentposition;

Fig. 6 is a diagrammatic view Similar to Figs. 4 and 5, showing thetrolley in a third position; and

Fig. 7 is la view showing a modiiled form.

As indicated in the statement of the objects of the invention, it may beused in connection with a traveling bridge type lcrane in which it isreouired that the trolley I which travels along the bridge 2 may berolled off from the bridge onto a spur track 3 (Fig. 3). So long as thetrolley is on the bridge. the bridge motor 4 (Figs. l, 4, 5, and 6)itself will have to be'under control. When the trolley is rolled oi thebridge onto the spur track 3, there is no bridge motor which has to becontrolled. It is desirable that this bridge motor 4 shall becontrollable by an operator traveling along with the trolley either onfoot on the foor underneath the trolley or in a cage carried by thetrolley.

The bridge is provided with trucks 4a suspended by hangers 4b from thetruck wheels 4c traveling along the runways I 'I and is propelled alongthese runways by means of traction wheels 4d engaging the under side vofthe runways I1 and driven from the bridge motor 4 by means of shafting4e extending longitudinally of the bridge. The hoist block 4f issuspended from the trolley I byvmeans of a chain 4g, one end of which isxed -to the trolley and the other end of which is connected -with thehoist motori. The trolley may be pro.-

`for operating the hoist and sometimes an additional operator-controlledmotor 6 for causing the trolley to travel back, and forth along thebridge. With thisconstruction, so long as the trolley is traveling onthe bridge, it will be necessary to have a power circuit both vfor the`bridge motor 4 and for the motors carried bythe trolley and to haveacontrol circuit-whereby the operator can control the rbridge motor. Thisrequires, in addition to the. ground return, two control conductors for`the bridge motor 4 extending theA lengthv of the bridge and two powerconductors for the trolley-carried motor extending the length of thebridge. In prior installations, this has required four additionalconductors extending thel length of the bridge, none of the conductorsbeing in lalignment with each other so that no one collector wouldengage more than one of the conductors;

When the trolley is run off from the bridge track onto a spur track 3,there isno need for the control conductors as the bridge motor is notthen in use. However, in order to keep the collectors which werev inengagement with the control bus bars on Ithe bridge from iiopping aroundas the trolley runs along the spur track, it has been proposed toprovide two additional vtracks along the spur trackway, not for thepurpose of carrying current but to keep' theseidle collectors fromflopping around.

In our improved system, the power bus bars 'I and-Iir on the bridge andthe control bus bars 9 and I Il .on the bridgearel made in staggeredsections connected byjumpers II so thatthe collectors carried by thevtrolley I, as theyftravel along .the bridge, will alternately engage.power Sections and control sectionsyof the bus bars. lIn order toinsure that there will always be one set of collectors in engagementwith a power section and another set in engagement with a controlsection, we have provided, in Iaddition to the trolley-carriedcollectors I2 which engage the ground return rail I3, three sets ofcollectors I4, I4a, I4b and I4c, I5, I5a, I5b and I5o, and I6, I6a; Ibandl |66, spaced apart from each other adistance slightly greater thanthe length of a bus bar section.

Referring to the drawings in detail, and rst to Figs. 1-6, incl., theconstruction shown therein comprises an electric traveling crane system,in-` cluding a bridge runway I 1, three power bus bars I8, I9 and 20extending longitudinally of the runway and forming a three-wire'circuit.the bus bar I9 being electrically connected with the runway I1, a bridge2 mounted to travel on this runway, a three-phase reversible bridgemotor 4 mounted on this bridge for causing the bridge to travel ineither direction along the runway. collectors 2l, 22 and 23 engaging thenower bus bars I8,k I9 and 2U.V respectively, a trolley trackwayconductor rail 24 mounted on the bridge on which the` trolley travelsand electrically connected with the collector 22, a pair of power busbars .1 and 8.extending alongside the trolley trackway rail I 3,electrically connected with the collectors 2| and 23. respectively,which engage the power bus `bars I8 and 2l),A respectively, a trolley'I' movable onto and oiT of the trolley trackwav 24. a trolley motor 6.and a hoist .motor mounted onk a` trolley, circuit controllingmechanism25 for controlling the forward and reverse rotation of the bridge motor4 comprisingan electrically ener-y gized switch-actuator 26 which, whenenergized, causes forward rotationY of. the bridge motor 4. aV secondelectrically energized switch-actuator 21 which. when energized, causesreverse rotation ofthe bridge motor, one side of each actuator beingelectrically connected with the trolley trackway rail I3, four setsofcollectors (1) I2,` (2) I4. Ida. I4b and I4c. (3) I5I5a. I5b and I5c.

` and (4) I6, I-6a, Ib and 16e. mounted on said trolley, the busbars 1and 8 having longitudinally spaced portions engageable anddisengagefable. by three of said sets ofcollectors I(2), (3) and (4)4and jumper ,portions II connecting said vlongitudinally spaced portionsnot engageable by said three sets of collectcrs, a pair of control busbars 9 and I Il extending alongside said trollev trackway rail YI3 andelectrically connected with Vthe other sidesA of the actuators26 and 21.re-` spectively, the control bus bars having longitudinally spacedportions lying between the spaced portions ,of the `bus bars l and 8engageable and Ydisengageable-by the above three sets of collectorsBridge motor control 'I'hecircuit control apparatus 'for controlling theenergization of the bridgev motor control, ac-

tuators 26 and 21 comprises a forward switch 28 "m and a reverse switch29, eachoi'v said switches Ycomprising three contacts 28a, V28h vand 28eand 29a, 29h and 29e, respectively, and a connector 28d and 29d,respectively, for connecting and disconnecting all three contacts withrespect .to each other, the three contacts 28a,"28b and' 28e of theforward switch being electrically connected with.

the three collectors I6a, I5a and I4a, respectively,

and the three contacts 29a, 29h and 29e of theV 4 respectively, andthree movable contacts 46, 41

Vnected with the power bus bar I3.

and'48 controlled by the actuator 21 and movable into andout .ofengagement with the contacts 43, 44 and 45, respectively, andelectrically connected with the three motor terminals 49, 50 and 5I.When this switch 42 is closed the bridge motor 4 maybe driven in whatmay be termed a forward direction. Ihe switch 4I comprises threecontacts 52, 53 and 54 electrically connected with the contacts 43, 44and 45 and hence electrically connected with the bus bars I3, 1 and 8,respectively, and three contacts 55, 56 and 51 actuated by the actuators26 and movable into and'out of engagement with the contacts 52, 53 and54, respectively. The movable contacts 55, 56 and 51 arev electricallyconnected with the movable contacts 46, 48 and 41, respectively, andhence with the three terminals 49, 50 and 5I on the bridge motor 4. Whenthe contacts of the switch 4I are brought into engagement, circuits willbe established for the bridge motor 4 which will cause the bridge motorto be rotated in what may be termed a reverse direction.

Power supplyfor trolley carried motors motor 5, one wire 3l beingelectrically connected with the fourth collector I2, a circuitcontroller 34 for the motors`5 and 6, three' circuit controllers 35, 36and 31 mounted on thetrolley I for controlling the circuits between theothertwo wires 32 and 33 and the bus bars 1 and 8, land threeelectrically energized actuators 38, 39and'46, one for each of saidcircuit controllers 35, 36 and 31.

The purpose of theY pairs of collector contacts I4 and I4b, I5 and I5b,and i6 and lh is tol control the actuators 38,39' and 40, respectively,in such a manner that at least one ofthem will be energized no matter'what' position the trolley occupies on the bridge. As long as any oneof them is energized, the conductors 32 and 33 leading to the trolleyand hoist motors will be electrically connected with the power bus bars1 and 8, respectively. As previously indicated, the spacing of thecollector contacts is such that at least one pair of each of the abovepairsv of collector contacts will be in engagement with a section of thepower bus bars 1 and 8 in all positions of the trolley on the trolleytrackway I3. As explained hereinafter, this will cause the conductors 33and 32 for theV controller 34 of the trolley-carried motors 5 and 6 tobe connected with the power bus bars 1 and 8. The third conductor 3| iscon- The circuit controller 35 comprises a pair of xed contacts 58 and59, electrically connected with the collectors I4a and 14o,respectively, and a pair of movable contacts 69 and 6I controlled by theactuator 38 connected with the conductors 33 and 32, respectively, andengageable and disengageable with respect tothe contacts 58 and 59.Conductors B2 and 63 lead from the contacts 58 and 59 to the switchcontacts 28e and 29o, respectively, of the bridge motor control switches28 and 29. The circuit controller 36 comprises a pair of xed contacts 64and 65, electrically connected with the current collectors Ia and I5c,respectively, and a pair of movable contacts 66 and 61 controlled by theactuator 39 and connected with the trolley motor conductors 33 and 32,respectively. The contacts 64 and 65 are also electrically connectedwith the switch contacts 28h and 29h` respectively. The circuitcontroller 31 comprises two fixed contacts 68 and 69, electricallyconnected with the current collectors I6a and I 6c, respectively, and apair of movable contacts and 1I controlled by the actuator 46 andelectrically connected with the contacts 33 and 32, respectively. Thecontacts 68 'and 69 are also electrically connected with the contacts28a .and 29a of the switches 28 and 29.

Power lines to trolley-carried motors in diferenr trolley positionsFigs. 4, 5 and 6 show the circuits with the trolley in three differentpositions on the bridge. In Fig. 4 the collectors I4, I 4a, I4b and I4care in engagement with sections of the control bus bars 9 and I0. Thecollectors I6, Ilia, I6b and I6c are also in engagement with sections ofthe control bus bars 9 and I0. 'I'hese two sets of collectors I4, I4a,I4b and I4c and I6, I6a, I6b and I6c, in effect, provide parallelcircuits and either circuit would be effective to produce the desiredresults. However, both are necessary at times, as will appearhereinafter. The intermediate collector contacts I5, I5a., I5b and I5care in engagement with the power bus bars 1 and 8. Un-

der these conditions, the actuator 39 will be energized and theactuators 38 and 40 will not be energized. The energization of theactuator 39 causes the contacts 66 and 61 to engage contacts 64 and 65,respectively. This energizes the wires 32 and 33 to make the circuitcomplete to the trolley-carried motors, the Wire 3I being connected tothe collector I2 which engages the bus bar I3.

In Fig. 5 the set of collectors I6, I6a, I6b and I6c are in engagementwith sections of the power bus bars 1 and 8. The other two sets ofcollectors I4, I4a, I4b and I4c and I5, I5a, I5b and I5c are inengagement with the control bus bars 9 and I0. Under these conditions,the actuator will be energized and the actuators 38 and 39 will not beenergized.v The energization of the actuator 40 causes the contacts 10and 1I to engage the contacts 68 and 69, respectively. This energizesthe wires 32 and 33 to make the circuit complete to the trolley-carriedmotors. Y

In Fig. 6 the collectors I4, I4a, I4b and I4c and I6, I6a, |612 and Icare both in engagement with sections of the power bus bars 1 and 8.Under these conditions, both the actuator 38 and ther actuator 48 willbe energized and the actuator 39 will not be energized. This will complete parallel circuits between the bus bars 1 and 8 and the wires 32and 33, either of the parallel circuits being suilicient to make thecircuit complete to the trolley-carried motors.

Control Zines to bridge motor in .different trolley positions withsectionsof the control bus bars 9 and I0. Under Vthese conditions, ifthe forward switch 28 is closed, the forward speed actuator 26 will beenergized by completing a circuit between bus bar I3 and 1, the circuitfor this actuator 26 being from the intermediate bus bar I3 through theconductors 12, 13 and 14, actuator 26, conductor 15, control bus bar 9,collector I4a, conductors 16 and 62, contact 28e, connector 28d, contact28h, conductors 11 and 18 and collector I5a to the power bus bar 1.

The energization of the actuator 26 brings the contacts 55, 56 and 51into engagement with the contacts 52, 53 and 54, respectively, thuselectrically connecting the motor terminals 49, and 5I with vthe busbars I3, 8 and 1, respectively. The circuit between terminal 49 and busbar I3 is through the conductors 19 and 86, contacts 55 and 52, andconductors 8I and 12. The circuit from the terminal 59 to the bus bar 8is through the conductors 82 and 83, contacts 51 and 54, and conductors84 and 85. The circuit Y from the terminal 5I to the busbar 1 is throughIsa, lsb and Isc are in Contact with sections of the power bus bars 1and 8, respectively, and the two sets of collectors I4, I4a, I4b and I4cand I6, I6a, I6b and I6c are' both in engagement the conductors 86 and91, contacts 56 and 53 and conductors 88 and 89. It may be assumed thatthis will give forward speed to the motor 4.

For reverse, the switch'29 is closed. This closes the circuit throughthe actuator 21 between the bus bars I3 and 8. The circuit through theactuator 21 is from the bus bar I3 through the conductors 12 and 13,actuator 21, conductor 99, con tro-l bus bar I6, collector I4c,`conductors 9I and B3, contacts 29e and 29h, conductors 92 and 93 andcollector I5c to the power bus bar 8.

The energization of the actuator 21 will cause the contacts 46, 41 and43 to engage the contacts 43, 44 and 45, respectively, thus electricallyconnecting the motor terminals 49, 58 and 5I with the bus bars I3, 1 and8, respectively. The circuit from the terminal 49 to the bus bar I3 isthrough the conductors 19 and 12. The circuit from the motor terminal'50 to the bus bar 1 is through the conductors 82 and 89. The circuitfrom the motor terminal 5I to the bus bar 8 is through the conductorsv86 and 85. It may be assumed that these motor connections will givereverse speed to the motor.

In Fig. 5 the collectors I6, I6a, |617 and I6c are electricallyconnected with the power bus barsl 1 and 8. The collectors I4, I4a, I4band I4c are in engagement with the control bus lbars 9 and I0. Thecollectors I5, 15a, I5b and I5c may be out of engagement both withrespect to the power bus bars 1 and 8 and the control bus bars 9 andII).r

Under these conditions if the forward switch 28 is closed, the actuator26 will be energized by a circuit therethrough between the bus bars I3and 1. yThis circuit is from the bus bar I3 through the conductors- 12,13 and 14, actuator 26, conductor 15,l control bus bar 9, collector I4a,conductors 16 and 62, contact 28e, connector 28d, contact 28a,conductors 94 and 95 and collector I6a to the power bus bar 1. Thisenergization of the. actuator 26 will connect the terminals 49, 50 and5I of the motor with the bus bars I3, 8 and 1, respectively, asdescribed in connection with Fig. 4, giving forward speed to the motor4.

If the reverse switch 29 is closed, the actuator 21 will beenergized bya circuit therethrough between the bus bars I3 and 8 This circuit isfrom the bus bar I3 through the conductorsl 12 and 13, actuator 21,conductor 98, control bus bar I8, collector I4c, conductors 9| and'63,contact 29o, connector 29d, contact 29a, conductors 96 and 91 andcollector I6c to the power bus bar 8. The

energization of the actuator 21 will connect. the motor terminals 49, 50and 5I with the bus'bars I3, 1 and' 8, respectively, as described inconnection with Fig. 4, giving reverse speed to the mo-V tor 4. f

In the trolley position shown in Fig. 6,'the set of collectors It,Illa', |41) and |4`c and the set of collectors I6, Ia, Ib'and |30 areboth in engagement lwith the power bus Vbars 1 and 8. The col-` lectorsvI5, |511, |517 and |5c are in engagement with the control -bus bars 9and I0. This arrangement'gives inV effect two parallel power circuitsthrough the two sets of collectors I4, |4a, |412 and |40 and I6, Ilia,IEb and |00. Under these conditions. if the switch 2B is closed,theactuator 26 will be energized by a circuit therethrough between thebus bars I3 and 8. This circuit is from bus bar 3 through the conductors12, 'I3 and 14,

actuator 26, conductor 15, control busbar 9, collector I 5a, conductors13 and 11, contact 28h, con'- nector 28d and through either or both ofthe contacts 28o and-28c to the power bus bar 1. The circuit from thecontact 28a to the bus bar 1 is through the conductors 94 and'95 and thecollector Isa. The circuit from the contact 28o to the bus bar 1 isthrough the conductors 62 and 19 and the collector Illa. Thisenergization of the actua'. tor 26 will connect the motor terminals 49,50 and 5| with the bus bars I3, 8 and 1, respectively, for forward speedof the bridge motor as described in connection with Fig. 4. y

If thereversing switch 29 is closed, the reversring actuator 21 will beenergized -by a circuit `therethrough between the bus bars I3 and 8,this circuit being from the bus bar I3 through the conductors 12 and 13,actuator 21, conductor 90,

Y control bus bar I0, collector I5, conductors 93 and 92, contact 29h,connector 29d, and through either or both of the contacts 29a and 29e byconductors 96 and 91 and collector |6c or by conductors 63 and 9| andcollector Illc to the power bus bar 8. YThis energization of `theactuator 21 will connect the motor terminals 49, 50 and 5| with Ithe busbars I3, 1 and 8, respectively, for

reverse speed as described in connection with Fig. 4. False operation ofthe actuators 26 and 21 is avoided by designing the a-ctuators 38, 39and 4] so Vthat their impedance is high enough to prevent suficientcurrent from passing to operate the actuators 25 and 2l. Y

The apparatus shown in Fig. '7 may be identical with, or the equivalentof, the construction shown in Figs. Ll, 5 and 6, except that in Fig. '7Y a substitution is made for the forward and reverse switches 28 and 29which, in Figs. 4, 5 and 6, control the forward switch circuits 62, T!-and 94 and the reverse switch circuits 63, 92 and 96. The substitutionmade in Fig. '7 enables the use of standard two-circuit switches insteado-f the three-circuit switches 28 and -29 of Fig. 4. The` substitutedapparatus comprises a power actuated forward switch 98, an electricallyenergized actuator 09 for'this switch, and a manually controlled switch|90 for controlling this actuator.`

The apparatus substituted for the reverse switch 29 comprises a poweractuated switch |0I, an

electrically energized actuator |02 therefor, and

gageable with respect to the contacts |04 and' |05 and both electricallyconnected with the conductor 94. The reverseswitch comprises two xedcontacts |08 `and |09 electrically connected wth the conductors 6 3 and96, respectively, and two contacts I|0 and III engageable anddisengageable with respect tothe contacts |08 and |09 andboth'electrically connected with the conductor 92. The circuit for theforward `switch actuator 99 is from the conductor 33, through theconductor H2, actuator 99, conductor II3, contact H4, connector ||5,contact |56 and conductor ||1 to the conductor 32. The circuit for thereverse switch actuator |92 is from the lconductor 33, through theconductors H2 and IIS, actuator |92, conductor ||9, contact |20,connector |2| and conductors |22 and Hl to the conductor 32. Inoperation, when the forward manual switch |00 is actuated, the actuator99 will be energized and all three conductors 62, 'Il and 94 will beconnected together just. as occurs when the forward switch 28 isoperated in Figs. 1l,y 5, and 6, so that the forward operation of themotor 4 will be broughtabout, Similarly, when the manual reverse switch|03 is operated, the reverse actuator |02 will bey energized, causingthe conductors 63, 92 and 96 to be all electrically connected just as.occurs when the reverse switch 29 of Figs. 4, 5 and 6 is operated. Thiswill cause reverse operation of the motor 4 just as occurs in Figs. 4, 5and 6.

Further modifications will be apparent to those skilled in the art andit is desired, therefore, that the invention be limited only by thescope of the appended claims.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

l. In an electric traveling crane system,` a

three-line bus bar power circuit, a bridge mounted to travel alongsidesaid circuit and having collectors mounted thereon for engaging said busbars, respectively, a three-line bus bar power circuit mounted on saidbridge and extending longitudinally thereof and electricallyconnectedwith said collectors, a three-phase bridge motor mounted on said bridge,a control-circuit for said bridge motor comp-rising a two-line bus barextending longitudinally of the bridge and mounted thereon, a trolleymounted to travel, longitudinally of said bridge, collectors mounted onsaid trolley for engaging said bridge mounted busbars, a three-phasemotor carried by said trolley, two of said bridge-mounted power `circuitbus bars having longitudinally-spaced portions engageable anddisengageable by their cooperating collectors, and jumper portions notengageable by said collectors, said control circuit havinglongitudinally-*spaced portions lying between said spaced portions ofthe power circuit and in alignment therewith and engageable anddisengageable by said cooperating collectors, one or more of saidtrolley mounted collectors being always in engagement with arcontrol busbar and one or more of said trolley mounted collectors being always inengagement with a power bus bar as the trolley travels along the bridge.means for controlling said bridge motor comprising means for connectinga collector engaging a control bus bar with a collector engagingva powerbus bar in alignment with said control bus bar, a three-line circuit forsaid trolley carried mo-V tor, and means for maintaining said three-linecircuit in electrical connection with said bridge mounted4 three-linebus bar power circuitvas the trolley travels along the bridge.

three-line bus bar power circuit, a bridge mounted to travel alongsidesaid circuit and having collectors mounted thereon for engaging said busbus bars, a three-phase motor carried by said trolley, two of saidbridge-mounted power circuit bus bars having longitudinally-,spacedportions engageable and disengageable byv their cooperating collectors,and jumper portions not engageable by said collectors, said controlcircuit having longitudinally-spaced portions lyingr .between saidspaced portions of the power circuit and in alignment therewith andengageable and disengageable by said cooperating collectors, saidcollectors comprising a plurality of sets of collectors spaced apart sothat there will always be at least one set having one vor morecollectors in engagement with one of said two bridge mounted power busbars and one or more collectorsr in engagement with the other of saidtwo bridge mounted power bus bars and `so` that there'will always be atleast one set having ylone or more collectors in engagement with one ofsaid control bus bars and one or more collectors in vengagement with theother control bus bar 'as the trolley travels along the bridge, meansfor controlling said bridge motor comprising means for connecting acollector engaging a control bus bar with a collector engaging a powerbus bar in alignment with said control bus bar, a threeline circuit forsaid trolley carried motor, and means vfor maintaining said three-linecircuit in electrical connection with said bridge mounted three-line busbar power circuit as the trolley travels along the bridge.

3. In an' electric traveling crane system, a three-line bus bar powercircuit, a bridge mounted to travel alongside said circuit and havingcollectors mounted thereon for engaging saidV bus bars, respectively, athree-line bus bar power circuit mountedon said bridge and extendinglongitudinally thereof and electrically connected with said collectors,a three-phase bridge motor mounted on said bridge, a control circuit forsaid bridge motor comprising a two-line bus bar extending longitudinallyof the bridge and mounted thereon, a trolley mounted to travellongitudinally oi said bridge, collectors mounted on said trolley forengaging said bridge mounted bus bars, a three-phase motor carried bysaid trolley, two of said bridge-mounted power circuit bus bars havinglongitudinally-spaced portions engageable and disengageable by theircooperating collectors, and jumper portions not engageable by saidcollectors, said control circuit having longitudinally-spaced portionslying between said spaced portions of the power circuit and in alignmenttherewith and engageable and disengageable by said cooperatingcollectors, said collectors comprising a plurality of sets of collectorsspaced apart so that there will always be at least one set having one ormore collectors in engagement with one of said two bridge mounted powerbus bars and one or more collectors in engagement with the other of saidtwo bridge mounted power bus bars and so that there will always be atleast one set having one or more collectors in engagement with onef ofsaid.

control bus bars and one or more collectors in engagement-withthe-'othery control ,bus bar as the trolleyA travels along the ,bridge,means for controllingsaid bridge" motor comprising means for connectinga collector engaging a control bus bar with vacollector engaging a powerbus bar` in alignment with saidjcontrol bus bar, a threeline Vcircuitfor said trolley carried motor, land means for vmaintaining saidthree-line circuit in electrical connection with said bridge mountedthree-line bus bar power circuit as the trolley travels along thebridge, said bridge motor control means comprising an electric actuatorfor causing. forward rotation of *the bridge motor, electricallyconnected with one control bus bar, and an electric actuator for causingreverse rotation of the bridge motor, electrically connected with theother control bus bar.

4,'In an electric traveling crane system, a three-line bus bar powercircuit, a bridge mounted to travel alongside said circuit and havingcollectors mounted thereon 'for engaging said bus bars, respectively, athree-line bus bar power circuit mounted on said bridge and extendinglongitudinally thereof andelectrically yconnected with said collectors,a three-phase bridge motorl mounted on said bridge, a control circuitforsaid bridge motor comprising a two-line bus bar extending longitudinallyof the bridge and mounted thereon, a'trolley mounted to travellongitudinally of said bridge,collectors mounted on said trolley forengaging said bridge mounted bus bars,

a three-phase vmotor carried by said trolley, twoy of saidbridge-mounted power circuitrbus bars having longitudinally-spacedportions engageable and disengageable by their cooperating collectors,andjumper portionsnot engageable by said collectors, said controlcircuit having longitudinally-spaced portions lying between said spacedportions of the power circuit and in alignment therewith and engageableand disengageable by said cooperating collectors, said collectorscomprising a plurality oi sets of collectors spaced apart so that therewill always be at least one set having Vone or more collectors inengagement with one of said ltwo bridge mounted power bus bars 4and oneor more .collectors in engagement with the other oisaid two bridgemounted power bus bars and so that there will always be at least one sethaving one or more collectors in engagement with one of said con--y trolbus bars and onel or more'collectors'in engagementv with the'othercontrol bus bar as the trolley travels along the bridge, means for-controlling said bridge motor comprising means Vfor with a collectorengageable with one of said twoY bridge mountedpower bus vbars and itsotherf side connected Witha collector Yengageable With the other of saidtwo bridge mounted bus bars.

5. In an electric traveling crane system, a threeline bus .barpower'rcircuit, a bridge mounted to travel alongside said circuitV andhaving collectors mounted thereon for engaging said bus bars,respectively, a three-line lbus barl power circuit mounted-on saidbridge-and extending longitudinally thereof and electrically connectedwith said collectors, a three-phase bridge motor'mounted on said bridge,a control circuit for said bridge motorcomprising a two-line bus barextending longitudinally of the bridge and mounted thereon, a trolleymounted to travel longitudinally of said bridge, collectors mounted onsaid trolley for engaging said bridge moun'ted bus bars, a threephasemotor carried by said trolley, two of said bridge-mounted power circuitbus bars'having longitudinally-spaced portions engageable andldisengageable by their cooperating collectors, and Y jumper portions notengageable by said collectors, said control circuit havinglongitudinally-spaced portions lying between said spaced portions of thepower circuit and in alignment therewith and i engageable anddisengageable by said cooperating collectors, said collectors comprisinga plurality of sets of collectors 'spaced apart so that therewill alwaysbe at leastione set having one or more collectors in engagement with oneof said two bridge mounted power bus bars and one or more collectors inengagement with the other of said two bridge mounted power bus rbars and,so that there will always be at least one set having one or morecollectors in engagement with one of said control bus bars and one ormore collectors in engagement with the other control bus bar as the:trolley travels along the bridge,V means for controllingsaid bridgemotor comprising means 0 for connecting a collector engaging a controlbus bar withV a collector engaging a power bus bar in alignment withsaid control bus bar, a three-line circuit for said trolley carriedmotor, and Vmeans ways in engagementwith a power bus bar as the trolleytravels along the bridge, means for controlling said bridge mountedmotor comprising means for connecting a lcollector engaging a controlbus bar'with a collector engaging a power bus barin alignment with saidcontrol bus bar, a motor circuit for said trolley-carried motor, andmeans for maintaining said'motor circuit in electrical connection withsaid bus bar power circuit as the trolley travels along the bridge.

7. A control system for controlling from a single control station a pairof electric motors, one of which is relatively stationary and the yotherof which is movable relative to said first motor, said control stationbeing mounted for movement with i said second motor, comprising athree-conductor actuator'having one side connected with a collectorengageable with' one of said two bridge mounted power bus bars and itsother side connected with'a collector engageable with the other of saidtwo bridge mounted bus bars.

power circuit extending along the path of movement of said second motor,two conductors of said circuit comprising longitudinally aligned spacedportions and connecting jumper portions disposed out of alignmentwithsaid spaced power portions, a control circuit including a pair ofcontrol conductors having longitudinally spaced portions disposedbetween and in alignment with said spaced power portions and jumperconnections between said spaced control portions, current collectorsmounted for movement with said second motor for engaging said power andcontrol conductors including a set of collectors for each of said twopower conductors, each of said sets including a plurality of collectorsso. spaced 1ongitudinally that at least one collector engages one ofsaid power portions and katY least one collector engages one of saidcontrol portions in all positions of said collector sets along the pathof movement of said second motor, control meansxedly mounted withrespect to said one motor and connected to said control circuit forselective energization therefrom, said control means being operable toselectively connect said one motor to said power circuit, means in saidmovable control station for selectively connecting one or the other ofsaid pair of control conductors to a corresponding one of said two powerconductors to operate said control means and energize said one motorregardless of the position of said control'station along said pathathree-conductor motor circuit for said second motor controllablefromsaid Y control station, and means for automatically main- 6. In anelectric traveling crane system, ab'ridge mounted to travel along atrack, a bus bar power circuit mounted on said bridge andr extendingAlongitudinally thereof, Ymeans for supplying en-j ergy to said powercircuit during travel of'said bridge, a bridge motor mounted on saidbridge, a control circuit for said bridge motor Vincluding two bus barsextending longitudinally of the bridge and mounted thereon, a trolleymounted to travel longitudinally of said bridge, collectors mounted onsaid trolley forengaging said bridge Y mounted bus bars, amotor carriedby said trolley,

two ofsaid power circuit bus bars having longitudinally spaced portionsengageable and disengageable by their cooperating collectors, and jumperportions not engageable by said collec# tors, said control circuit busbars having longitudinally Vspaced portions lying between said spacedportions of the power circuitand'inalignl ment therewithY andengageablev -andy disengageable by said Vcooperating collectors, 'one ormore of said trolley mountedcollectors being `always in engagement witha'control bus'bar andY one or` more offsaid trolley' mounted collectorsbeing alf taining electrical connections between said motor circuit andsaid power circuit through said collectors as said second motor movesalong said pathand said collectors in said sets' sequentially engage andY, disengage said spaced control and power portions. 55

8. A control system for controlling from a single control station a pairof electric motors, .one of which. is relatively stationary ,and theother of which is movable relative to said rst motor, said controlstation being mounted for movement with said second motor, comprising apower circuit extending along the path of Vmovement of said secondmotor, two `conductors of said cir-` cuit comprisinglongitudinally-,aligned spaced portions and connecting jumper portionsdisposed out of alignment with said spaced power portions,

a control circuit including a pair of control conductors havinglongitudinally-spaced portions disposed between andY in alignment withsaid spaced power portions and jumper connections between said spacedcontrol portions, current collectors mounted for movement with saidsecond motor for engaging said power and control conductors including aset of collectors for each"of said twoV power conductors, each ofsaidsets including a plurality of Vcollectors so spaced Ylongitudinally thatat least one collector engages one of said power portions and at leastone collector engages one of said control portions in all positions ofsaid collector sets along the path of movement of said second motor,control means iixedly mounted with respect to said one motor andconnected to said control circuit for selective energization therefrom,said control means being operable to selectively connect said one motorto said power circuit, means in said movable control station forselectively connecting one or the other of said pair of controlconductors to a corresponding one of said two power conductors tooperate said control means and energize said one motor regardless of theposition of said control station lalong said path, a motor circuit forsaid second motor controllable from said control station, and means forautomatically maintaining electrical connections between said motorcircuit and said power circuit through said collectors as said secondmotor moves along said path and said collectors in said setssequentially engage and disengage said spaced control and powerportions.

9. In a transfer crane bridge system of the type having a bridge movablein a xed path between a plurality of positions, in at least one of whichpositions said bridge is alignable with a branch track, and a trolleymovable longitudinally of said bridge and movable onto said branch trackwhen said bridge is in said one position, said bridge and said trolleyeach having a motor mounted thereon, the combination of a threeconductorpower system mounted on and extending longitudinally of said bridge, twoof said power conductors comprising aligned longitudinallyspacedportions and connecting jumper portions disposed out of alignment withsaid spaced portions, a control circuit including a pair of controlconductors having longitudinally-spaced aligned portions extendingbetween and insulated from said spaced power conductor portions, jumpersconnecting said spaced portions of said control conductors, collectorson said trolley for engaging said three-conductor power circuitincluding a set of collectors for each of said two power conductorsadapted, to sequentially engage and disengage said aligned spaced powerportions and control portions as said trolley moves along said bridge,the collectors in each set being so spaced longitudinally that in allpositions of said trolley along said bridge at least onecollector`engages one of said power portions and at least one collectorengages one of said control portions, control means on said bridgeconnected to said control circuit for selectively connecting said bridgemotor to said power circuit, a control station on said trolley connectedbetween said collectors for selectively connecting one or the other ofsaid control conductors with the corresponding one of said two powerconductors to effect operation of said bridge motor ,control meansregardless of the position of said trolley along said bridge, athree-conductor circuit for said trolley motor, and means formaintaining electrical connections between said three-conductor trolleymotor circuit and said three-conductor power circuit as said trolleytravels along said bridge and said collector sets engage and disengagesaid spaced conductor portions. l

10. In a transfer crane bridge system of the type having a bridge trackalong which a bridge is movable between a plurality of positions, saidbridge including a trolley track extending longitudinally of said bridgeand being alignable in at least one oi said bridge positions with abranch track, said bridge also having a trolley movable longitudinallythereof on said trolley track and movable from said trolley track ontosaid branch track when said bridge is in said one position, said bridgeand said trolley each having a three-phase reversible motor mountedthereon, the combination of a three-phase three-conductor power systemextending along said bridge track and having oneconductor thereofconnected to ground, collectors carried by said bridge and engaging saidconductors, one of said bridge collectors connecting said groundedconductor to said trolley track, a pair of power conductors extendingalong said trolley track electrically connected to the others of saidbridge collectors, said pair of trolley conductors and said trolleytrack forming a threeconductor three-phase power circuit for saidtrolley motor, two conductors of said circuit comprisinglongitudinally-aligned spaced portions and connecting jumper portionsdisposed out of alignment with said spaced power portions, a controlcircuit including a pair of control conductors havinglongitudinally-spaced portions disposed between and in alignment withsaid spaced power portions and jumper connections between said spacedcontrol portions, current collectors mounted for movement with saidtrolley motor for engaging said power and control conductors including aset of collectors for each of said two power conductors, each of saidsets'including a plurality of collectors so spaced longitudinally thatat least one collector engages one of said power portions and at leastone collector engages one of said control portions in all positions ofsaid collector sets along the path of movement of said trolley motor,control means iixedly mounted with respect to said bridge motor andconnected to said control circuit for selective energization therefrom,said control means being operable to selectively connect said bridgemotor to said power circuit, means in said movable control station forselectively connecting one or the other of said pair of controlconductors to a corresponding one of said two power conductors tooperate said control means and energize said bridge motor regardless ofthe position of said control station along said path, a three-conductormotor circuit for said trolley motor controllable from said controlstation, and means for. automatically maintaining electrical connectionsbetween said motor circuit and said power circuit through saidcollectors as said trolley motor moves along said path and saidcollectors in said sets sequentially engage and disengage said spacedcontrol and power portions.

RALPH W. SPAFFORD. LLOYD R. BERGREN.

